Nick Valenty, 39, died of "multiple sharp force injuries," according to the Hennepin County Medical Examiner's office. Valenty lived in the Park Apartments at 15th Street East and Spruce Place, and his body was found lying near an apartment building on Willow Street, across from Loring Park's Berger Fountain.

Police and the medical examiner's office are not releasing details of the victim's injuries. But the victim's brother, Chris Valenty, said police informed him that the victim had been stabbed at least three times, once on each side of the neck and once in the chest.

"The police said that the person who did this knew what they were doing, meaning they knew how to kill someone," Valenty said. "This isn't a mugging."

Valenty said his brother also was beaten, though Allen, commander of Downtown's First Precinct, said that is not his understanding. And because the victim's wallet was missing, robbery is remains a possible motive, Allen said.

Chris Valenty believes his brother's murder might have been a homosexual hate crime, even though his family never knew the 39-year-old's sexual preference.

"I do feel that due to the severity of the murder that this was a hate crime, based on that he was different and that [the killer] probably thought he was gay," Valenty said. "And for all we know, he might have been."

Nick Valenty was trained as a classical and jazz pianist, though he almost never played in public, according to his brother. He was also a composer whose work was too difficult to teach other musicians and perform publicly, Chris Valenty said.

Nonetheless his brother's tastes ran the gamut from classical to punk rock, and he rarely missed a concert Downtown. Chris Valenty thinks the victim likely was on his way to a show when he was assaulted at about 7:45 p.m.

"He was probably walking through the park because he thought it was beautiful," he brother said. "He loved animals and nature."

Nick Valenty graduated valedictorian at Forest Lake High School and received graduate honors from Macalester College, where he studied music. He was also something of a quirky character, he brother said, suffering torment as a child because he was "different."

"People who are really smart, sometimes they lack social skills -- maybe they just decide they don't need them," Chris Valenty said. "Maybe they just see right through that."

Ben Riley, leasing agent at the Park Apartments where Valenty lived, said he always paid his rent early, and had occupied the same apartment since 1986. He never caused problems, Riley said.

At the time of his death, Valenty was working for a Downtown workers-compensation insurance firm, his brother said.

Riley said he is shocked by the brutality of Valenty's death.

"If you know the guy, that's the last thing you would expect," Riley said. "If someone wanted his wallet they could have just walked up to him and said, 'Give me your wallet,' and he would have handed it over."

Allen said he is surprised police have found no witnesses. There generally is foot and vehicle traffic near the park on Saturday evenings, although a Twins game broadcast might have cut down on some of that, Allen said. Additionally, it was cold, and nearby apartment windows likely were closed, he said.

Police have made no arrests and Allen said none are pending.

"At this point," Allen said, "it remains one of the most challenging cases that we're going to face in a long time."